Cosmic ray antiprotons and modified closed galaxy model

Calculations based on accelerator data for the production of antiprotons and existing models for the propagation of cosmic rays, predict too small a flux of antiprotons compared with the finite flux observed recently. Using a 'modified closed galaxy' model this excess is attributed here to secondary antiprotons. In this model approximately 50% of the observed cosmic ray nucleons are of recent origin and they propagate according to the 'nested leaky box' model, while the rest propagate according to 'closed galaxy' model. This model explains the observations on antiproton and e+, and predicts more D and 3He than do the existing models. (U.K.)